Do đó
[TEX]{\color{Blue} \frac{a}{b}+\frac{b}{a}=\frac{b+m}{b}+\frac{b}{b+m}=1+\frac{m}{b}+\frac{b}{b+m}\geq 1+\frac{m}{b+m}+\frac{b}{b+m}=2 \\\\ \Leftrightarrow \frac{a}{b}+\frac{b}{a}\geq 2(dpcm)[/TEX]
Do đó
[TEX]{\color{Blue} \frac{a}{b}+\frac{b}{a}=\frac{b+m}{b}+\frac{b}{b+m}=1+\frac{m}{b}+\frac{b}{b+m}\geq 1+\frac{m}{b+m}+\frac{b}{b+m}=2 \\\\ \Leftrightarrow \frac{a}{b}+\frac{b}{a}\geq 2(dpcm)[/TEX]